My app uses iCloud to let users sync their files via their private iCloud Drive, which does not use CloudKit.
FileManager.default.url(forUbiquityContainerIdentifier: nil)?.appending(component: "Documents")
I plan to transfer my app to another developer account, but I'm afraid it will affect the access of the app to the existing files in that folder. Apple documentation doesn't mention this case.
Has anyone done this before and can confirm if the app will continue to work normally after transferring?
Thanks
iCloud & Data
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On the macOS platform, I am planning to use the combination of NSFileProviders Custom Action and userInfo to implement custom context menus. However, the NSExtensions FileProviders Action Activation Rule in info does not work as long as it is related to userInfo. Are there any restrictions on the use of this userInfo? keepDownloaded is bool value
I'm building a photo editing app with a token-based subscription system using RevenueCat and StoreKit. Users purchase subscriptions that grant tokens for AI generations. There are no user accounts, the app is fully anonymous.
Currently, I generate an anonymous account ID via RevenueCat SDK and store it in iCloud Keychain. This allows users on the same iCloud account to restore both their subscription and token balance across devices. However, users on a different iCloud account can restore their subscription via Apple, but their token balance is lost because there's no way to link the anonymous IDs.
The problem is that if a user switches iCloud accounts or gets a new device without the same iCloud, their purchased tokens are orphaned. The subscription restores fine through Apple, but the token balance tied to the old anonymous ID becomes inaccessible.
I have a few constraints: no user accounts, no email or phone sign-in, must work across devices owned by the same person, and must comply with App Store guidelines.
My questions are: Is iCloud Keychain the right tool for this, or is there a better approach? Would CloudKit with an anonymous record zone be more appropriate? Are there any recommended patterns for persisting consumable balances tied to anonymous users across device migrations?
Any guidance would be appreciated.
Topic:
App & System Services
SubTopic:
iCloud & Data
Hello,
I recently published an app that uses Swift Data as its primary data storage. The app uses concurrency, background threads, async await, and BLE communication.
Sadly, I see my app incurs many fringe crashes, involving EXC_BAD_ACCESS, KERN_INVALID_ADDRESS, EXC_BREAKPOINT, etc.
I followed these guidelines:
One ModelContainer that is stored as a global variable and used throughout.
ModelContexts are created separately for each task, changes are saved manually, and models are not passed around.
Threads with different ModelContexts might manipulate and/or read the same data simultaneously.
I was under the impression this meets the usage requirements.
I suspect perhaps the issue lies in my usage of contexts in a single await function, that might be paused and resumed on a different thread (although same execution path). Is that the case? If so, how should SwiftData be used in async scopes?
Is there anything else particularly wrong in my approach?
I am trying to test using Testflight and have set up a test with a user on an account I also own which is different to me developer account. The app I believe is running in production on a separate device and is working from a user point of view, however I am not able to query the data via the console. As I said I know the user id and password as tey are mine so even when I use the Act as user service it logs in but the query is empty. I'm assuming I'm not doing anything wrong its possibly an security issue that is preventing me accessing this account. My question to the group then is how do I verify the data that is being tested?
Hello! I’ve been trying to log in to my iCloud account, but I haven’t been able to access it. A message pops up saying, 'Couldn’t communicate with the server.' Additionally, I can’t update my phone to the latest iOS version. Please, how can I resolve this?
Topic:
App & System Services
SubTopic:
iCloud & Data
About 4 months ago, I shipped the first version of my app with 4 versioned schemas that, unintentionally, had the same versionIdentifier of 1.2.0 in 2 of them:
V1: 1.0.0
V2: 1.1.0
V3: 1.2.0
V4: 1.2.0
They are ordered correctly in the MigrationPlan, and they are all lightweight.
Migration works, SwiftData doesn't crash on init and I haven't encountered any issues related to this. The app syncs with iCloud.
Questions, preferable for anybody with knowledge of SwiftData internals:
What will break in SwiftData when there are 2 duplicate numbers?
Not that I would expect it to be safe, but does it happen to be safe to ship an update that changes V4's version to 1.3.0, what was originally intended?
Topic:
App & System Services
SubTopic:
iCloud & Data
Hi everyone,
I am experiencing an iCloud provisioning problem I cannot resolve, and Developer Support has not been able to help.
My App ID:
com.exaqservices.ArkyvTiles
Symptoms:
1. In Xcode (v16.2), enabling iCloud in Signing & Capabilities repeatedly fails with:
The app ID does not include the iCloud container. Click Try Again.
Clicking Try Again does nothing. The error persists forever.
2. In Certificates, Identifiers & Profiles:
• The iCloud capability is enabled for this App ID.
• The CloudKit container is selected.
• But the portal no longer shows the “iCloud Documents” checkbox, which used to be required for ubiquitous document support.
3. Xcode cannot regenerate provisioning profiles because it claims the App ID is missing the iCloud container — even though the container is attached.
4. Provisioning profiles on the Apple Developer site all appear expired, and new ones do not generate correctly.
5. The App Store Connect interface also does not show an iCloud Services section under App Information → Capabilities as older guides describe.
Expected Behavior:
Since iCloud and the CloudKit container are enabled on the App ID, Xcode should successfully enable:
• com.apple.developer.icloud-services
• com.apple.developer.icloud-container-identifiers
• com.apple.developer.ubiquity-container-identifiers (if needed)
• com.apple.developer.ubiquity-kvstore-identifier
Instead, the entitlements never propagate.
What I suspect:
This seems like an App ID metadata mismatch or a stale backend entry where:
• the CloudKit container is attached but the entitlement isn’t linked,
• the “iCloud Documents” flag is missing due to a UI transition,
• provisioning profiles cannot be regenerated because the App ID is not updating correctly.
What I need help with:
Can someone from Apple engineering confirm:
• Whether my App ID metadata is corrupted,
• If entitlements need to be manually refreshed,
• Or if the “iCloud Documents” toggle has moved or is no longer exposed?
This is blocking development completely — I cannot build, sign, or deploy the app with iCloud.
Thank you!
Alan Metzger
I built a SwiftData App that relies on CloudKit to synchronize data across devices.
That means all model relationships must be expressed as Optional.
That’s fine, but there is a limitation in using Optional’s in SwiftData SortDescriptors (Crashes App)
That means I can’t apply a SortDescriptor to ModelA using some property value in ModelB (even if ModelB must exist)
I tried using a computed property in ModelA that referred to the property in ModelB, BUT THIS DOESN”T WORK EITHER!
Am I stuck storing redundant data In ModelA just to sort ModelA as I would like???
We have an unreleased SwiftData app for iOS18+. While we were testing I saw reports on the forum about unexpected database migrations for codable arrays on iOS26.1.
I'd like to ask a couple of questions:
1- Does this issue originate from the new Xcode version, or is it specific to iOS 26.1?
2- Is it possible to change our attribute so that users on older iOS versions receive the same model, preventing a migration from being triggered when they upgrade to iOS 26.1?
One of our models looks like this:
struct Point: Codable, Hashable {
let x: Int
let y: Int
}
@Model
class Grid {
private(set) var gridId: String = ""
var points: [Point] = []
var updatedAt: Date = Date()
private(set) var createdAt: Date = Date()
#Index<Grid>([\.gridId])
...
}
I can think of some options like:
// 1
@Attribute(.transformable(by: CustomJsonTransformer.self)) var points: [Point] = []
// 2
@Attribute(.externalStorage) var points: [Point] = []
// 3
var points: Data = Data() // store points as data
However, I'm not sure which one to use.
What would you recommend to handle this, or is there a better strategy you would suggest?
When creating a new project in Xcode 26, the default for defaultIsolation is MainActor.
Core Data creates classes for each entity using code gen, but now those classes are also internally marked as MainActor, which causes issues when accessing managed object from a background thread like this.
Is there a way to fix this warning or should Xcode actually mark these auto generated classes as nonisolated to make this better? Filed as FB13840800.
nonisolated
struct BackgroundDataHandler {
@concurrent
func saveItem() async throws {
let context = await PersistenceController.shared.container.newBackgroundContext()
try await context.perform {
let newGame = Item(context: context)
newGame.timestamp = Date.now // Main actor-isolated property 'timestamp' can not be mutated from a nonisolated context; this is an error in the Swift 6 language mode
try context.save()
}
}
}
Turning code gen off inside the model and creating it manually, with the nonisolated keyword, gets rid of the warning and still works fine. So I guess the auto generated class could adopt this as well?
public import Foundation
public import CoreData
public typealias ItemCoreDataClassSet = NSSet
@objc(Item)
nonisolated
public class Item: NSManagedObject {
}
When I used to do Migrations, I always used ETL and then push to a dev system to review/test before going production.
The migration support is SwiftData is fine for a little tweak.
I might as well just just use new schema and context and write the custom code than use the SwiftData migration support.
Hi all, I've contacted Apple about this privately but I wanted to post this publicly too just to see if anyone else is experiencing the same issue. We use CloudKit to store "documents" (we'll call them) for our users. We use it directly, not via CoreData etc but through the lower level APIs.
This has been working great for the last 9 months or so. Since a few days ago we've started receiving reports from users that their data has disappeared without a trace from their app. Obviously this is very serious and severe for us. We keep a local copy of the users data but if CloudKit tells us this data has been deleted we remove that local copy to keep in sync.
Nothing has changed client side in terms of our code, and the only way we can see that could cause this, is a fetch that we perform asking for a list of the users "documents" is returning no rows/results, or possibly returning rows with invalid or missing fields.
We have about 30,000 active users per day (1.5m requests/day) using CloudKit and we have only a handful of reports of this. Again this only started happening this week after 9 months of good service.
Has anyone else noticed anything "strange" lately, fetches returning empty? fields missing? Is anyone at Apple aware of any recent changes to CloudKit? or outages? We're really unsure how or who should handle this and who we can escalate to? Any help appreciated.
We have a workaround/mitigation on the way through review at the moment but this is a really big problem for us if we can't rely on CloudKit to remember users data reliably.
I'm experiencing a critical issue with SwiftData custom migrations where objects created during migration appear to be inserted successfully but aren't persisted or found by queries after migration completes. The migration logs show objects being created, but subsequent queries return zero results.
I'm migrating from schema version V2 to V2_5, which involves:
Renaming Person class to GroupData
Keeping the same data structure but changing the class name while keeping the old class.
Using a custom migration stage to copy data from old to new schema
Below is an extract of my two schema and migration plan:
Environment:
Xcode 16.0,
iOS 18.0,
Swift 6.0
SchemaV2
enum LinkMapV2: VersionedSchema {
static let versionIdentifier: Schema.Version = .init(2, 0, 0)
static var models: [any PersistentModel.Type] {
[AnnotationData.self, Person.self, History.self]
}
@Model
final class Person {
@Attribute(.unique) var id: UUID
var name: String
var photo: String
var requirement: String
var statue: Bool
var annotationId: UUID?
var number: Int = 0
init(id: UUID = UUID(), name: String = "", photo: String = "", requirement: String = "", status: Bool = false, annotationId: UUID? = nil, number: Int = 0) {
self.id = id
self.name = name
self.photo = photo
self.requirement = requirement
self.statue = status
self.annotationId = annotationId
self.number = number
}
}
}
Schema V2_5
static let versionIdentifier: Schema.Version = .init(2, 5, 0)
static var models: [any PersistentModel.Type] {
[AnnotationData.self, Person.self, GroupData.self, History.self]
}
// Keep the old Person model for migration
@Model
final class Person {
@Attribute(.unique) var id: UUID
var name: String
var photo: String
var requirement: String
var statue: Bool
var annotationId: UUID?
var number: Int = 0
init(id: UUID = UUID(), name: String = "", photo: String = "", requirement: String = "", status: Bool = false, annotationId: UUID? = nil, number: Int = 0) {
self.id = id
self.name = name
self.photo = photo
self.requirement = requirement
self.statue = status
self.annotationId = annotationId
self.number = number
}
}
// Add the new GroupData model that mirrors Person
@Model
final class GroupData {
@Attribute(.unique) var id: UUID
var name: String
var photo: String
var requirement: String
var status: Bool
var annotationId: UUID?
var number: Int = 0
init(id: UUID = UUID(), name: String = "", photo: String = "", requirement: String = "", status: Bool = false, annotationId: UUID? = nil, number: Int = 0) {
self.id = id
self.name = name
self.photo = photo
self.requirement = requirement
self.status = status
self.annotationId = annotationId
self.number = number
}
}
}
Migration Plan
static let migrationV2toV2_5 = MigrationStage.custom(
fromVersion: LinkMapV2.self,
toVersion: LinkMapV2_5.self,
willMigrate: { context in
do {
let persons = try context.fetch(FetchDescriptor<LinkMapV2.Person>())
print("=== MIGRATION STARTED ===")
print("Found \(persons.count) Person objects to migrate")
guard !persons.isEmpty else {
print("No Person data requires migration")
return
}
for person in persons {
print("Migrating Person: '\(person.name)' with ID: \(person.id)")
let newGroup = LinkMapV2_5.GroupData(
id: person.id, // Keep the same ID
name: person.name,
photo: person.photo,
requirement: person.requirement,
status: person.statue,
annotationId: person.annotationId,
number: person.number
)
context.insert(newGroup)
print("Inserted new GroupData: '\(newGroup.name)'")
// Don't delete the old Person yet to avoid issues
// context.delete(person)
}
try context.save()
print("=== MIGRATION COMPLETED ===")
print("Successfully migrated \(persons.count) Person objects to GroupData")
} catch {
print("=== MIGRATION ERROR ===")
print("Migration failed with error: \(error)")
}
},
didMigrate: { context in
do {
// Verify migration in didMigrate phase
let groups = try context.fetch(FetchDescriptor<LinkMapV2_5.GroupData>())
let oldPersons = try context.fetch(FetchDescriptor<LinkMapV2_5.Person>())
print("=== MIGRATION VERIFICATION ===")
print("New GroupData count: \(groups.count)")
print("Remaining Person count: \(oldPersons.count)")
// Now delete the old Person objects
for person in oldPersons {
context.delete(person)
}
if !oldPersons.isEmpty {
try context.save()
print("Cleaned up \(oldPersons.count) old Person objects")
}
// Print all migrated groups for debugging
for group in groups {
print("Migrated Group: '\(group.name)', Status: \(group.status), Number: \(group.number)")
}
} catch {
print("Migration verification error: \(error)")
}
}
)
And I've attached console output below:
Console Output
I'm trying to use the new (in tvOS 26) video streaming service automatic login API from the VideoSubscriberAccount framework:
https://developer.apple.com/documentation/videosubscriberaccount/vsuseraccountmanager/autosignintoken-swift.property
It seems that this API requires an entitlement. This document suggests that the com.apple.smoot.subscriptionservice entitlement is required.
https://developer.apple.com/documentation/videosubscriberaccount/signing-people-in-to-media-apps-automatically
However, it seems more likely that com.apple.developer.video-subscriber-single-sign-on is the correct entitlement.
https://developer.apple.com/documentation/bundleresources/entitlements/com.apple.developer.video-subscriber-single-sign-on
Which is the correct entitlement and how do I obtain it?
I don't want to fully comply with the video partner program.
https://developer.apple.com/programs/video-partner/
I just want to use this one new automatic login feature.
Hi everyone,
Im trying to set up CloudKit for my Unreal Engine 5.4 project but seem to be hitting some roadblocks on how to set up the Record Types.
From my understanding I need to set up a "file" record type with a "contents" asset field - but even with this it doesn't seem to work :(
Any unreal engine devs with some experience on this who could help me out?
Thanks!
Hi there
We're using CloudKit in our app which, generally, syncs data perfectly between devices. However, recently the sync has stopped working (some changes will never sync and the sync is delayed for several days even with the app open on all devices). CloudKit's logs show the error „You can't save and delete the same record" and „Already have a mirrored relationship registered for this key", etc. We’ve a hunch that this issue is related to a mirrored relationship of one database entity.
Our scenario:
We've subclassed the database entities.
The database model (which we can't share publicly) contains mirrored relationships.
We store very long texts in the database (similar to a Word document that contains markup data – in case that’s relevant).
Deleting all data and starting with a completely new container and bundle identifier didn’t help (we tried that multiple times).
This issue occurs on macOS (15.2(24C101) as well on iOS (18.2).
Any hints on how to get the sync working again? Should we simply avoid mirrored relationships?
Many thanks
My Code:
let op = CKModifyRecordsOperation(recordIDsToDelete:recordIDsToDelete)
op.modifyRecordsCompletionBlock = { _, deleteRecordIDs, error in
if error == nil {
print("successful delete deleteRecordIDS = \(deleteRecordIDs)")
} else {
print("delete error = \(error?.localizedDescription)")
}
}
op.database = CKContainer.default().privateCloudDatabase
op.qualityOfService = .userInitiated
CKContainer.default().privateCloudDatabase.add(op)
My problem is that CKRecord are not deleted once I reinstall the app: when I reinstall the app and try to delete a CloudKit record, the method is executed successfully (error is nil) but the records are still in CloudKit Dashboards.
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
CloudKit
CloudKit Dashboard
CloudKit Console
Hey,
For some reason I see crashes for my iOS app related to CloudKit entitlements.
The crash happens on start up and it says:
"CKException - Application has malformed entitlements. Found value "*" for entitlement com.apple.developer.icloud-services, expected an array of strings"
I have checked my entitlements of the same build on App Store Connect and it shows "com.apple.developer.icloud-services: ( "CloudKit" )"
So I am not sure why users are having this issue. I haven't been able to reproduce it.
Does anyone have any idea why this is happening?
Thanks
I have not had any successful Schema Migration with CloudKit so far so I'm trying to do with with just very basic attributes, with multiple Versioned Schemas
This is the code in my App Main
var sharedModelContainer: ModelContainer = {
let schema = Schema(versionedSchema: AppSchemaV4.self)
do {
return try ModelContainer(
for: schema,
migrationPlan: AppMigrationPlan.self,
configurations: ModelConfiguration(cloudKitDatabase: .automatic))
} catch {
fatalError("Could not create ModelContainer: \(error)")
}
}()
var body: some Scene {
WindowGroup {
ItemListView()
}
.modelContainer(sharedModelContainer)
}
And this is the code for my MigrationPlan and VersionedSchemas.
typealias Item = AppSchemaV4.Item3
enum AppMigrationPlan: SchemaMigrationPlan {
static var schemas: [any VersionedSchema.Type] {
[AppSchemaV1.self, AppSchemaV2.self, AppSchemaV3.self, AppSchemaV4.self]
}
static var stages: [MigrationStage] {
[migrateV1toV2, migrateV2toV3, migrateV3toV4]
}
static let migrateV1toV2 = MigrationStage.lightweight(
fromVersion: AppSchemaV1.self,
toVersion: AppSchemaV2.self
)
static let migrateV2toV3 = MigrationStage.lightweight(
fromVersion: AppSchemaV2.self,
toVersion: AppSchemaV3.self
)
static let migrateV3toV4 = MigrationStage.custom(
fromVersion: AppSchemaV3.self,
toVersion: AppSchemaV4.self,
willMigrate: nil,
didMigrate: { context in
// Fetch all Item1 instances
let item1Descriptor = FetchDescriptor<AppSchemaV3.Item1>()
let items1 = try context.fetch(item1Descriptor)
// Fetch all Item2 instances
let item2Descriptor = FetchDescriptor<AppSchemaV3.Item2>()
let items2 = try context.fetch(item2Descriptor)
// Convert Item1 to Item3
for item in items1 {
let newItem = AppSchemaV4.Item3(name: item.name, text: "Migrated from Item1 on \(item.date)")
context.insert(newItem)
}
// Convert Item2 to Item3
for item in items2 {
let newItem = AppSchemaV4.Item3(name: item.name, text: "Migrated from Item2 with value \(item.value)")
context.insert(newItem)
}
try? context.save()
}
)
}
enum AppSchemaV1: VersionedSchema {
static var versionIdentifier: Schema.Version = Schema.Version(1, 0, 0)
static var models: [any PersistentModel.Type] {
[Item1.self]
}
@Model class Item1 {
var name: String = ""
init(name: String) {
self.name = name
}
}
}
enum AppSchemaV2: VersionedSchema {
static var versionIdentifier: Schema.Version = Schema.Version(2, 0, 0)
static var models: [any PersistentModel.Type] {
[Item1.self]
}
@Model class Item1 {
var name: String = ""
var date: Date = Date()
init(name: String) {
self.name = name
self.date = Date()
}
}
}
enum AppSchemaV3: VersionedSchema {
static var versionIdentifier: Schema.Version = Schema.Version(3, 0, 0)
static var models: [any PersistentModel.Type] {
[Item1.self, Item2.self]
}
@Model class Item1 {
var name: String = ""
var date: Date = Date()
init(name: String) {
self.name = name
self.date = Date()
}
}
@Model class Item2 {
var name: String = ""
var value: Int = 0
init(name: String, value: Int) {
self.name = name
self.value = value
}
}
}
enum AppSchemaV4: VersionedSchema {
static var versionIdentifier: Schema.Version = Schema.Version(4, 0, 0)
static var models: [any PersistentModel.Type] {
[Item1.self, Item2.self, Item3.self]
}
@Model class Item1 {
var name: String = ""
var date: Date = Date()
init(name: String) {
self.name = name
self.date = Date()
}
}
@Model class Item2 {
var name: String = ""
var value: Int = 0
init(name: String, value: Int) {
self.name = name
self.value = value
}
}
@Model class Item3 {
var name: String = ""
var text: String = ""
init(name: String, text: String) {
self.name = name
self.text = text
}
}
}
My experiment was:
To create Items for every version of the schema
Updating the typealias along the way to reflect the latest Item version.
Updating the Schema in my ModelContainer to reflect the latest Schema Version.
By AppSchemaV4, I have expected all my Items to be displayed/migrated to Item3, but it does not seem to be the case.
I can only see newly created Item3 records.
My question is, is there something wrong with how I'm doing the migrations? or are migrations not really working with CloudKit right now?